Currently, a user needs to undergo respective procedures for logon authentication before he or she can access each of the services provided by a plurality of Internet information systems and Internet service providers. In this way, the user has to remember several user passwords, which complicates the use of these systems by the user and increases the probability of error occurrence. Besides, the risk of suffering from illegal interception and damage is heightened, leading to security loosening of security. Furthermore, if the user forgets one of the user passwords, he or she cannot carry out a corresponding task and has to ask for help from an administrator. The user can only wait before regaining his or her password. This contributes to the overhead of system and security management resource and lowers work efficiency.